The manufacture of electrical equipment such as a flat display panel or a solar panel often needs dividing of a brittle substrate such as a glass substrate. A scribe line is first formed on a substrate, and the substrate is then divided along the scribe line. The scribe line can be formed by mechanically processing the substrate with a cutter. The cutter slides or rolls on the substrate, thus forming a trench on the substrate through a plastic deformation and forming a vertical crack directly below the trench. Subsequently, a stress is applied to the substrate in a step referred to as a breaking step. The crack fully penetrates in the thickness direction in the breaking step, so that the substrate is divided.
The step of dividing the substrate is often performed immediately after the step of forming a scribe line in the substrate. Alternatively, it is proposed to perform the step of processing the substrate between the step of forming a scribe line and the breaking step. The step of processing the substrate is, for example, the step of providing a member on the substrate.
According to the technique of WO 2002/104078, for example, a scribe line is formed on a glass substrate per area that serves as an organic EL display before mounting a sealing cap onto the substrate in the method for manufacturing an organic EL display. This method avoids the contact between the sealing cap and the glass cutter that might occur if the scribe line were formed on the glass substrate after providing the glass substrate with the sealing cap.
According to the technique of WO 2003/006391, for example, two glass substrates are bonded to each other after the formation of scribe lines thereon in the method for manufacturing a liquid crystal display panel. This method breaks two brittle substrates simultaneously in a single breaking step.